PB2033: INFLUENCE OF INDUCTION THERAPY WITH LENALIDOMIDE ON MAINTENANCE THERAPY AND PROGNOSIS AFTER AUTOLOGOUS STEM CELL TRANSPLANTATION IN PATIENTS WITH MULTIPLE MYELOMA
Authors: Q. Sun, J. Liu, B. Huang, J. Gu, X. Li, J. Li
Journal: HemaSphere (2022)

Background: We have finished a single-center, prospective study registered at www.chictr.org.cn (ChiCTR1900021558). 60 newly diagnosed multiple myeloma (NDMM) patients were included from 2017 to 2018, which were divided into lenalidomide, liposomal doxorubicin, and dexamethasone (RAD) group (n=30) or bortezomib, liposomal doxorubicin, and dexamethasone (PAD) group (n=30). Patients received 4-6 cycles of RAD or PAD induction therapy every 4 weeks, with subsequent autologous stem cell transplantation (ASCT) and maintenance therapy. This prospective study showed that the failure rate of stem cell mobilization in the RAD group was significantly higher than that in the PAD group. The hematopoietic reconstruction time in the RAD group was longer than that in the PAD group. Aims: Comparison of the process of maintenance therapy, efficacy, and prognosis between RAD induction and PAD induction in patients in previous clinical studies. Methods: Patients who completed induction therapy, ASCT, and received maintenance therapy through the previous clinical trial in our center were retrospectively analyzed. We divided enrolled patients into two groups according to the induction regimens, and compared maintenance treatment discontinuation, efficacy, time to progress (TTP), and overall survival (OS) between the RAD group and the PAD group. Results: 21 patients in the PAD group and 12 patients in the RAD group were enrolled in the study, the median follow-up time was 44.6 months. 28 patients received thalidomide and 5 received lenalidomide at the beginning of maintenance therapy. The rate of maintenance treatment discontinuation was higher in the RAD group compared to the PAD group (41.7% vs. 4.8%, P=0.016), but the interval of maintenance treatment discontinuation was not statistically different (1.0 month vs. 0.9 months, P=0.917). During maintenance treatment, patients in the RAD group had a lower median count of white blood cells than the PAD group (2.96×109/L vs. 3.38×109/L, P=0.033), and so did the median count of platelets (102×109/L vs. 150×109/L, P=0.011). The incidence of grade 3/4 hematologic adverse events (AEs) was also higher in the RAD group than in the PAD group (66.7% vs. 28.6%, P=0.033). The ratio of patients who achieved CR and MRD-negative in the RAD group was lower than those in the PAD group (P=0.047 and 0.016, respectively). The median TTP and median OS were not reached in both groups, but the median TTP and OS in the RAD group were shorter than those in the PAD group (P=0.032 and 0.022, respectively). Reinfusion of CD34+ cells <2×106/L was an independent prognostic factor for TTP (P=0.009); minimum count of platelets <50×109/L might be an independent prognostic factor for OS (P=0.050). Summary/Conclusion: Patients who received the RAD induction had worse efficacy and prognosis after receiving maintenance therapy compared to the PAD group, possibly due to discontinuation of maintenance therapy caused by a higher incidence of grade 3/4 hematologic AEs.